Image transfer via optical fibers requires the carefully positioned assembly of very large fiber arrays. Usually this is done by producing a large number of individual fibers and then assembling them in a coherent assembly process which may include the use of a plastic filler material to retain the fibers in the proper alignment. The task of orienting and aligning these fibers can be very difficult. In one prior art method of producing one dimensional arrays individual optic fibers are laid in parallel in a holder and a series of spacers is laid between them. The array is then heated to soften the spacers and bind together the fibers. When the array is cooled the fibers are effectively bound together by the spacers. The arrays so formed may be stacked.
In the present invention directed to the preparation of optical fiber ribbon cable, a flat ribbon is hot rolled or extruded and the fiber array is formed from it (i.e. the individual fibers in the ribbon are delineated) by altering the refractive index of alternate strips using mechanical techniques or diffusion techniques. A textured or corrugated surface ribbon or sheet can also be prepared by hot rolling or extrusion to produce a large one dimensional array of fibers.